American Sweetgum

Plant Characteristics

Habit		tree
Lifespan:	⌛	perennial

Cultivation

Features:	✓	deciduous, fall color

Scientific Names

Altingiaceae >

Liquidambar >

styraciflua >

Liquidambar styraciflua (American Sweetgum, Redgum) is a deciduous tree in the genus Liquidambar native to warm temperate areas of eastern North America. A popular ornamental tree in North America, it is recognizable from its combination of five-pointed star-shaped leaves and spiked fruit.

Autumn foliage and fruit

It is a medium-sized to large tree, growing to 20-35 m (exceptionally 41 m) tall, with a trunk up to 2 m diameter. The leaves are palmately lobed, 7-19 cm (rarely to 25 cm) long and broad and with a 6-10 cm petiole, looking somewhat similar to those of some maples. They have five sharply pointed lobes, but are easily distinguished from maples in being glossy and leathery in appearance, and arranged alternately, not in opposite pairs. They are a rich dark green and glossy, and in most cases turn brilliant orange, red, and purple colors in the autumn. A small percentage of trees are evergreen or semi-evergreen, with negligible fall color, especially in the extreme southern part of its range. In the northern part of its range, as well as in colder areas that it has been planted in, the leaves are often killed by frost while still green. The roots are fibrous; juices are balsamic.

The starry five-pointed leaves of the Liquidambar suggest the Sugar Maple, and its fruit balls as they hang upon their long stems resemble those of the Buttonwood. The distinguishing mark of the tree, however, is the peculiar appearance of its small branches and twigs. The bark attaches itself to these in plates edgewise instead of laterally, and a piece of the leafless branch with the aid of a little imagination readily takes on a reptilian form; indeed, the tree is sometimes called Alligator-wood.

The male and female inflorescences are on different branches of the same tree. The fruit, popularly nick-named a "space bug", "monkey ball", "bommyknocker", "bir ball", "gumball" "cukoo-bir" or "sticky ball", is a hard, dry, globose, compound fruit 2.5-4 cm in diameter and composed of numerous (40-60) capsules. Each capsule has a pair of terminal spikes (for a total of 80-120 spikes), and each capsule contains one to two small seeds. When the fruit opens and the seeds are released, each capsule is associated with a small hole (40-60 of these) in the compound fruit.

The autumnal coloring is not simply a flame, it is a conflagration; in reds and yellows it equals the maples, and in addition it has the dark purples and smoky browns of the ash.

• Bark: Light brown tinged with red, deeply fissured, ridges scaly. Branchlets pithy, many-angled, winged, at first covered with rusty hairs, finally becoming red brown, gray or dark brown.
• Wood: Bright reddish brown, sapwood nearly white; heavy, straight, satiny, close-grained, not strong; will take a beautiful polish; warps badly in drying. Has been used with good results in the interior finish of sleeping-cars and fine houses. The wood is usually cut in veneers and backed up with some other variety which shrinks and warps less. Sp. gr., 0.5910; weight of cu. ft., 36.83 lbs.
• Winter buds: Yellow brown, one-fourth of an inch long, acute. The inner scales enlarge with the growing shoot, becoming half an inch long, green tipped with red.
• Leaves: Alternate, three to five inches long, three to seven inches broad, lobed, so as to make a star-shaped leaf of five to seven divisions, these divisions acutely pointed, with glandular serrate teeth. The base is truncate or slightly heart-shaped. They come out of the bud plicate, downy, pale green, when full grown are bright green, smooth, shining above, paler beneath. In autumn they vary in color from yellow through crimson to purple. They contain tannin and when bruised give a resinous fragrance. Petioles long, slender, terete. Stipules lanceolate, acute, caducous.
• Flowers: March to May, when leaves are half grown; monoecious, greenish. Staminate flowers in terminal racemes two to three inches long, covered with rusty hairs; the pistillate in a solitary head on a slender peduncle borne in the axil of an upper leaf. Staminate flowers destitute of calyx and corolla, but surrounded by hairy bracts. Stamens indefinite; filaments short; anthers introrse. Pistillate flowers with a two-celled, two-beaked ovary, the carpels produced into a long, recurved, persistent style. The ovaries all more or less cohere and harden in fruit. Ovules many but few mature.
• Fruit: Multicapsular spherical head, an inch to an inch and a half in diameter, hangs on the branches during the winter. The woody capsules mostly filled with abortive seeds resembling sawdust.

Read about American Sweetgum in the Standard Cyclopedia of Horticulture

Liquidambar styraciflua, Linn. Sweet Gum. Bilsted. Alligator Tree. Fig. 2182. Tree, 60-140 ft. high: lvs. 5-7- lobed, with acuminate, finely serrate lobes, lustrous and dark green above, paler below and glabrous except large tufts of pale rufous hairs in the axils of the principal veins, 3—7 in. across; petioles 5-6 in. long: fr. 1-1½ in. across. March-May. Conn, and S. N. Y to Fla., I11., Mo. and Mex. The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

Cultivars

Mature "monkey ball" after seed dispersal

Selected cultivars:

• 'Burgundy' – dark red to purple fall colors may persist through winter.
• 'Clydesform' - sold as Emerald Sentinel; columnar or narrowly pyramidal; slow growth to 9 meters; yellow-orange fall colors.
• 'Festival' – columnar; pale green summer leaves; bright fall hues of yellow, pink and red; less hardy than most.
• 'Goduzam' (Gold Dust) – variegated; pink to red-purple in fall.
• 'Grazam' – pyramidal, with glossy leaves. Orange, red and purple fall colors.
• 'Gumball' – dwarf shrubby cultivar seldom more than 2 meters tall. Purple-red fall color.
• 'Moraine' – upright, rounded form, fast growth, red fall color, hardy to −30 °C.
• 'Palo Alto' – various shades of red in fall; best in California.
• 'Parasol' – develops rounded crown; mature height 10 meters; deep red fall color.
• 'Rotundiloba' – sterile cultivar with rounded lobes on leaves. Originally discovered in North Carolina in the 1930s.
• 'Slender Silhouette' - very narrow columnar form.
• 'Worplesdon' – cutleaf cultivar with orange, red and purple fall colors.

Gallery

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  Liquidambar styraciflua summer foliage cluster

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  Immature "monkey ball" showing the paired capsule spikes

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  Liquidambar styraciflua Mature bark of American Sweetgum Hemingway, South Carolina

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  Liquidambar styraciflua cultivated at Keokea, Maui, Hawaii

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  Liquidambar styraciflua leaves. Texas A&M University in College Station, Texas.

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  Liquidambar styraciflua at the Texas A&M University in College Station, Texas.

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  American sweetgum taken in autumn at the parc de Rentilly, France.

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  Liquidambar styraciflua bloom at Clear Creek Park in Crawford County, Arkansas

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  Liquidambar styraciflua in early fall colors at West Point, NY

References

• Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963

External links

• w:American Sweetgum. Some of the material on this page may be from Wikipedia, under the Creative Commons license.
• American Sweetgum QR Code (Size 50, 100, 200, 500)